Which type of intermolecular force is the strongest present in a sample of hydrogen fluoride (HF)?

• A. Dipole-dipole interactions
• B. Ion-dipole interactions
• C. London dispersion forces
• D. Hydrogen bonding

Answer: (D)

Verified step by step guidance

1. Identify the types of intermolecular forces that can be present in hydrogen fluoride (HF). These include London dispersion forces, dipole-dipole interactions, and hydrogen bonding.
2. Recall that London dispersion forces are weak forces present in all molecules due to temporary dipoles, but they are generally the weakest type of intermolecular force.
3. Recognize that dipole-dipole interactions occur between polar molecules where permanent dipoles attract each other. HF is a polar molecule, so dipole-dipole forces are present.
4. Understand that hydrogen bonding is a special, stronger type of dipole-dipole interaction that occurs when hydrogen is directly bonded to highly electronegative atoms like fluorine, oxygen, or nitrogen. Since HF has hydrogen bonded to fluorine, hydrogen bonding is possible.
5. Conclude that among the listed options, hydrogen bonding is the strongest intermolecular force present in HF because it involves a highly polar bond and strong attraction between molecules.